I recieved this 4.5V Airhead as a prize for helping set up the Mnpls leg of the WOH tour.
I got it home and took it apart!
According to Headroom's website the difference between a Total Airhead and an Airhead are better resistors in the signal path and Oscon elctrolytic capacitors in place of the regular caps. I'm not able to get better resistors but I did have some Cerafines in the same value so I slapped 'em in.
The result? I thought the amp was 'Tinny' when I first got it and now it's a respectable little amp. Pretty solid bass and nice presentation. I'd keep it if I didn't have this DIY habit to support.
Price for a new Airhead is $119 and a Total Airhead is $199. This unit is new except for the surgery which is offset, I think, by the quality of the caps hence my price of $120 shipped to your door with the Straightwire interconnect.